Hello,
I have a little problem with undocumented instructions:
on the site http://www.z80.info/z80undoc.htm we have
- OR IYH which is coded FD B4
- OR IYL which is coded FD B5
Or z80asm (Z80 assemble version 1.8 Copyright (C) 2002-2007 Bas Wijnen <shevek@fmf.nl>) does the opposite!
Should I trust the site or the software?
Thank you.
Undocumented instructions OR IY
Re: Undocumented instructions OR IY
https://clrhome.org/table/#or%20ixl
says OR IXL is DDB5.
I use Visual Studio Code with some extensions like Z80 Assembly Meter and Z80 Instruction Set and they tell the same thing. And so is the assembler I use. So I believe z80asm is wrong.
Same for ASM80 online:
says OR IXL is DDB5.
I use Visual Studio Code with some extensions like Z80 Assembly Meter and Z80 Instruction Set and they tell the same thing. And so is the assembler I use. So I believe z80asm is wrong.
Same for ASM80 online:
Re: Undocumented instructions OR IY
I posted an issue the savannah.nongnu.org but it seems there is already one because it seems to be fixed now:
https://git.savannah.nongnu.org/cgit/z8 ... 6cb37c6cc2
https://git.savannah.nongnu.org/cgit/z8 ... 6cb37c6cc2
Re: Undocumented instructions OR IY
Yes I just recompiled it, and it works for all codes except compounds:
RLC (IX + nn) & LD R, (IX + nn) etc ...
RRC (IX + nn) & LD B, (IX + nn)
RL (IX + nn) & LD B, (IX + nn)
RR (IX + nn) & LD B, (IX + nn)
SLA (IX + nn) & LD B, (IX + nn)
SRA (IX + nn) & LD B, (IX + nn)
SLL (IX + nn) & LD B, (IX + nn)
SRL (IX + nn) & LD B, (IX + nn)
RES B, (IX + nn) & LD B, (IX + nn) etc ...
SET B, (IX + nn) & LD B, (IX + nn) etc ...
and these codes are unknown
SLL R
IN F, (C)
OUT F, (C)
Besides, there is no more compact notation for codes composed of 2 instructions?
RLC (IX + nn) & LD R, (IX + nn) etc ...
RRC (IX + nn) & LD B, (IX + nn)
RL (IX + nn) & LD B, (IX + nn)
RR (IX + nn) & LD B, (IX + nn)
SLA (IX + nn) & LD B, (IX + nn)
SRA (IX + nn) & LD B, (IX + nn)
SLL (IX + nn) & LD B, (IX + nn)
SRL (IX + nn) & LD B, (IX + nn)
RES B, (IX + nn) & LD B, (IX + nn) etc ...
SET B, (IX + nn) & LD B, (IX + nn) etc ...
and these codes are unknown
SLL R
IN F, (C)
OUT F, (C)
Besides, there is no more compact notation for codes composed of 2 instructions?
Re: Undocumented instructions OR IY
IN F,(C) is an aberration (as the same way as JP (HL) instead of JP HL) should be IN (C) because we don't store value from data bus into F register.
You mean OUT (C),0 ?
You mean OUT (C),0 ?
Re: Undocumented instructions OR IY
There is RASM which allows compact notation like:
- PUSH AF, BC, HL, DE -> PUSH AF : PUSH BC : PUSH HL : PUSH DE
- SRL HL -> SRL H : RR L
And so on.
- PUSH AF, BC, HL, DE -> PUSH AF : PUSH BC : PUSH HL : PUSH DE
- SRL HL -> SRL H : RR L
And so on.
Re: Undocumented instructions OR IY
I was thinking especially for this kind of notation:
RRC (IX + nn) & LD B, (IX + nn)
which corresponds to an undocumented code
On http://www.z80.info/z80undoc.htm there is a list of undocumented code and among others the IN F, (C) and OUT F, (C) are part of it but with a "?", so i imagine never tested.
RRC (IX + nn) & LD B, (IX + nn)
which corresponds to an undocumented code
On http://www.z80.info/z80undoc.htm there is a list of undocumented code and among others the IN F, (C) and OUT F, (C) are part of it but with a "?", so i imagine never tested.
Re: Undocumented instructions OR IY
IN F,(C) is known as IN (C) in assemblers which handle it.
All undocumented opcodes are known: https://baltazarstudios.com/z80explorer/.
https://baltazarstudios.com is in my opinion a great website to master all the aspects of Z80 (including what is done under M-cycles/T-states and even half-cycles) and has a lot schematics explaining in details each part.
All undocumented opcodes are known: https://baltazarstudios.com/z80explorer/.
https://baltazarstudios.com is in my opinion a great website to master all the aspects of Z80 (including what is done under M-cycles/T-states and even half-cycles) and has a lot schematics explaining in details each part.
Re: Undocumented instructions OR IY
I have just compiled it, it is excellent as software ... I adopt! thank you.